阅读说明：本技术 无需热处理强化的高强铸造铝合金及其制备方法 (High-strength cast aluminum alloy without heat treatment strengthening and preparation method thereof ) 是由 程帅 应辉 唐号然 杜燕军 于 2019-11-06 设计创作，主要内容包括：本申请公开一无需热处理强化的高强度铸造,其中所述无需热处理强化的高强度铸造铝合金以下成分：8.0-13重量％的硅、最多0.4重量％的铁、2-4重量％的镁、2-4重量％的铜、0.3-0.8重量％的锰、1-3重量％的锌、0.01-0.07重量％的钛、最多0.02重量％的镍、最多0.2重量％的铅、0.1-0.3重量％的铬、其余为铝的铝合金,高压铸造而形成。(high strength casting without heat treatment strengthening, wherein the high strength casting aluminum alloy without heat treatment strengthening is formed by high pressure casting of 8.0 to 13 wt% silicon, up to 0.4 wt% iron, 2 to 4 wt% magnesium, 2 to 4 wt% copper, 0.3 to 0.8 wt% manganese, 1 to 3 wt% zinc, 0.01 to 0.07 wt% titanium, up to 0.02 wt% nickel, up to 0.2 wt% lead, 0.1 to 0.3 wt% chromium, and the balance aluminum.)

1, A high strength cast aluminum alloy strengthened without heat treatment, characterized in that it consists of:

8.0-13 wt% silicon;

up to 0.4 wt.% iron;

2-4% by weight of magnesium;

2-4% by weight of copper;

0.3-0.8 wt.% manganese;

1-3% by weight of zinc;

0.01-0.07 wt% titanium;

up to 0.02 wt% nickel;

up to 0.2 wt% lead;

0.1-0.3 wt% chromium;

the balance being aluminum alloy.

2. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 1, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 9.0-12.0 wt.% silicon.

3. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 2, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises at most 0.3 wt.% iron.

4. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 3, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 2.5-3.5 wt.% magnesium.

5. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 4, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 2.5-3.5 wt.% magnesium.

6. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 5, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 2.5-3.5 wt.% copper.

7. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 6, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 0.4-0.7 wt.% manganese.

8. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 7, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 1.7-2.3 wt.% zinc.

9. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 8, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 0.04-0.06 wt.% titanium.

10. The high strength cast aluminum alloy not subject to heat treatment strengthening of claim 9, wherein the high strength cast aluminum alloy not subject to heat treatment strengthening comprises at most 0.01 wt.% nickel, the high strength cast aluminum alloy not subject to heat treatment strengthening comprises at most 0.1 wt.% lead, and the high strength cast aluminum alloy not subject to heat treatment strengthening comprises 0.15-0.25 wt.% chromium.

Technical Field

The invention relates to the field of high-strength cast aluminum alloys, in particular to high-strength cast aluminum alloy without heat treatment strengthening.

Background

The casting forming technology is which is the most common forming method for metal parts and components and is widely applied to the industries of aerospace, automobiles, energy sources, consumer electronics and the like.

The high-strength cast aluminum alloy is used for producing safety parts with complex shapes and thin wall thicknesses, and the flowability and solidification characteristics of the aluminum alloy material have great influence on the performance, price and the like of products in the aluminum alloy parts produced by the pressure casting forming process, particularly products with complex shapes, uneven wall thicknesses and thin overall wall thicknesses.

Aluminum alloy products used in the communication industry are not suitable for improving the strength of cast aluminum alloy by means of heat treatment, because the method for manufacturing high-strength aluminum alloy inevitably improves the production efficiency and reduces the production cost. Thus, strength can only be ensured by die casting material molding.

At present, in order to meet the requirements of high-strength and high-plasticity parts, particularly good casting fluidity and ductility, the most commonly used pressure casting parts of A380 type have the as-cast properties of about 160MPa tensile yield strength Rp0.2 and more than 3.5% elongation at break A, and the tensile strength is more than 320MPa, but cannot meet the current market demand;

in addition, in addition to the requirement for high strength, parts produced by high pressure casting processes are required to have good corrosion resistance and fatigue resistance, and in addition, high pressure cast aluminum alloy products are required to have good dimensional stability to ensure assemblability.

Disclosure of Invention

objects of the present invention are to provide a high strength cast aluminum alloy which is strengthened without heat treatment, wherein the high strength cast aluminum alloy is suitable for use in making telecommunication aluminum alloy equipment, wherein the high strength cast aluminum alloy has a tensile yield limit Rp0.2 of >260MPa and simultaneously an elongation at break A of > 1.8%, a tensile strength Rm of >380MPa in the as-cast state, and a Brinell hardness of >110HB in the as-cast state.

Another objects of the present invention are to provide high strength cast aluminum alloy that does not require heat treatment for strengthening, wherein the high strength cast aluminum alloy can meet the strength requirements of communication equipment by high pressure casting without heat treatment for strengthening.

Another objects of the present invention are to provide high strength cast aluminum alloy without heat treatment for strengthening, wherein the high strength cast aluminum alloy can greatly improve elongation stability by high pressure casting without heat treatment for strengthening, so that a product made of the high strength cast aluminum alloy has good plasticity.

Another objects of the present invention are to provide high strength cast aluminum alloys that are strengthened without heat treatment and that are less expensive to produce because they do not require a heat treatment step.

Another objects of the invention are to provide high strength cast aluminum alloys that are strengthened without heat treatment, wherein the high strength cast aluminum alloys have good corrosion resistance and fatigue properties, and wherein the high pressure cast aluminum alloy products also need to have good dimensional stability to ensure assemblability.

It is another objects of the present invention to provide a high strength cast aluminum alloy that is strengthened without heat treatment, wherein the high strength cast aluminum alloy has good structural uniformity, particularly a uniform microstructure with controllable composition, to ensure good castability and mold filling properties, as well as good solidification characteristics.

To achieve at least the objects above, the present invention provides a high strength cast aluminum alloy that is strengthened without heat treatment, having the following composition:

8.0-13 wt% silicon;

up to 0.4 wt.% iron;

2-4% by weight of magnesium;

2-4% by weight of copper;

0.3-0.8 wt.% manganese;

1-3% by weight of zinc;

0.01-0.07 wt% titanium;

up to 0.02 wt% nickel;

up to 0.2 wt% lead;

0.1-0.3 wt% chromium;

the remainder of the aluminum alloy is formed by high pressure casting.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 9.0-12.0 wt.% silicon.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes at most 0.3 wt.% iron.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 2.5 to 3.5 wt.% magnesium.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 2.5 to 3.5 wt.% magnesium.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 2.5-3.5 wt.% copper.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 0.4 to 0.7 weight percent manganese.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 1.7-2.3 wt.% zinc.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 0.04 to 0.06 wt.% titanium.

In accordance with an embodiment of the invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes up to 0.01 wt.% nickel.

In accordance with an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes at most 0.1 wt.% lead.

According to an embodiment of the present invention, the high strength cast aluminum alloy that is strengthened without heat treatment includes 0.15 to 0.25 weight percent chromium.

Further objects and advantages of the invention, , will be fully apparent from the ensuing description.

These and other objects, features and advantages of the present invention will become more fully apparent from the following detailed description, wherein the appended claims are taken in conjunction with the accompanying drawings.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It is to be understood that the term "" should be interpreted as "at least " or " or more," i.e., in embodiments, elements may be in number, and in other embodiments, the element may be in number, and the term "" should not be interpreted as limiting the number.

a preferred embodiment of the invention will be described in detail below as a high strength cast aluminum alloy that is strengthened without heat treatment and is formed by high pressure casting an aluminum alloy having a composition of 8.0-13 weight percent silicon, up to 0.4 weight percent iron, 2-4 weight percent magnesium, 2-4 weight percent copper, 0.3-0.8 weight percent manganese, 1-3 weight percent zinc, 0.01-0.07 weight percent titanium, up to 0.02 weight percent nickel, up to 0.2 weight percent lead, 0.1-0.3 weight percent chromium, and the balance aluminum.

In the above-mentioned high-strength cast aluminum alloy which is not subjected to heat treatment strengthening, the fluidity and solidification feeding characteristics of the alloy melt are greatly improved by virtue of the uniformity of the microstructure, and the alloy is particularly suitable for products which are extremely complicated in shape and have thin walls and thick walls concentrated in parts, such as aluminum alloy products for communication.

In addition, in the above-mentioned high-strength cast aluminum alloy which does not need heat treatment strengthening, the elongation stability of the pressure cast product is greatly improved and the dimensional stability is also improved correspondingly thanks to the uniformity of the microstructure.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 9.0 to 12.0 wt.% silicon. When the silicon content is controlled within the range, the high-strength cast aluminum alloy which does not need heat treatment strengthening has good fluidity, low solidification shrinkage and extremely low casting hot cracking tendency.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes at most 0.3 wt.% iron.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 2.5 to 3.5 weight percent magnesium.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 2.5 to 3.5 weight percent magnesium. When the magnesium content is controlled within the range, the strength of a product formed by manufacturing the high-strength cast aluminum alloy without heat treatment strengthening can be effectively improved, and the elongation at break can be regulated and controlled.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 2.5 to 3.5 wt.% copper.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 0.4 to 0.7 weight percent manganese.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 1.7 to 2.3 wt.% zinc.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 0.04 to 0.06 weight percent titanium.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes up to 0.01 wt.% nickel.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes at most 0.1 wt.% lead.

Preferably, the high strength cast aluminum alloy that is not heat treated for strengthening includes 0.15 to 0.25 weight percent chromium. When the chromium content is controlled within the range, the cast structure of the alloy can be refined, and the strength and the plasticity of the product are effectively improved.

In the above-mentioned cast aluminum alloy, the form of eutectic silicon can be modified by adding strontium, and the formation of a fine rod-like eutectic silicon structure by the formation of coarse flaky silicon phases is avoided. The modified eutectic silicon has great influence on the mechanical properties of products made of the high-strength cast aluminum alloy without heat treatment strengthening, and particularly can greatly improve the elongation at break.

In the above-mentioned high strength cast aluminum alloy which is not strengthened by heat treatment, the combination of iron and manganese can greatly improve the tendency of the cast product to be stuck during pressure casting without sacrificing the elongation. By adding at most 0.3 weight percent of iron and at most 0.70 weight percent of manganese, the formation of coarse flaky AlFeSi phase (which has great influence on the plasticity of the product) can be avoided, and the formed quaternary AlSiMnFe phase has a regular polygonal shape, fine and uniform particle size distribution and small influence on the plasticity.

In the above-mentioned cast aluminum alloy, the combination of titanium and boron can greatly reduce the size of the primary aluminum phase and improve the elongation and tensile ultimate strength of the cast aluminum alloy. By adding at most 0.06 wt.% titanium and 0.01-0.05 wt.% boron, the formation of coarse primary aluminum phases in the barrel of the high-pressure casting device of the aluminum alloy melt can be avoided and the texture homogeneity of the high-pressure cast product is greatly improved. And moreover, the fluidity and the dimensional stability of the cast aluminum alloy can be improved, the product deformation caused by natural aging is reduced, and the yield is improved.

The mechanical properties and the natural ageing after 1 month of standing of the new cast aluminium alloy are shown in the table below.

Therefore, the high-strength cast aluminum alloy without heat treatment strengthening is particularly suitable for manufacturing high-strength parts, particularly high-strength low-toughness mobile phone middle plates required in the market at present.

It will be appreciated by persons skilled in the art that the embodiments of the invention described and illustrated above are given by way of example only and are not limiting of the invention. The objects of the invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.